scholarly journals Studies on the level of neutralizing antibodies produced by inactivated COVID-19 vaccines in the real world

2021 ◽  
Author(s):  
Haiying Zhang ◽  
Yuyuan Jia ◽  
Ying Ji ◽  
Xu Cong ◽  
Yan Liu ◽  
...  
Keyword(s):  
Real World ◽  
Linear Correlation ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Igg Antibodies ◽  
Serum Samples ◽  
The Real ◽  
Significant Difference ◽  
Positive Rate ◽  
High Linear Correlation

Background Although effective vaccines have been developed against COVID-19, the level of neutralizing antibodies (Nabs) induced after vaccination in the real world is still unknown. To evaluate the level and persistence of NAbs induced by two inactivated COVID-19 vaccines in China. Methods and findings Serum samples were collected from 1,335 people aged 18 and over who were vaccinated with COVID-19 inactivated vaccine in Peking University People's Hospital from January 19 to June 23, 2021, for detection of COVID-19 antibodies. The WHO standard of SARS-CoV-2 NAbs was detected. The coefficients of variation between the detection results and the true values of the NAbs detected by the WHO standard were all lower than the WHO international standard 3% after the dilution of the original and the dilution of the theoretical concentrations of 500 IU/mL, 250 IU/mL, 125 IU/mL, 72.5 IU/mL, 36.25 IU/mL and 18.125 IU/mL. On day 11-70, the positive rate of NAbs against COVID-19 was 82% to 100%; From day 71 to 332, the positive rate of NAbs decreased to 27%. The level of NAbs was significantly higher at 3-8 Weeks than at 0-3 Weeks. There was a high linear correlation between NAbs and IgG antibodies in 1335 vaccinated patients. NAbs levels were decreased in 31 of 38 people (81.6%) at two time points after the second dose of vaccine. There was no significant difference in age between the group with increased and decreased neutralizing antibody levels (x2 =-0.034, P>0.05). The positive rate of NAbs in the two-dose vaccine group (77.3%) was significantly higher than that in the one-dose group (18.1%), with statistical difference (x2=312.590, P<0.001). A total of 206 people who were 11-70 days after receiving the second dose were tested and divided into three groups: 18-40 years old, 41-60 years old and >60 years old. The positive rates of NAbs in three groups (18-40 years old, 41-60 years old and >60 years old) were 95.14%, 78.43% and 81.8%, respectively. The positive rate of NAbs was significantly higher in 18-40 years old than in 41-60 years old (x2=12.547, P <0.01). The titer of NAbs in 18-40 years old group was significantly higher than that in 41-60 years old group (t=-0.222, P <0.01). The positive rate of NAbs in male group (89.32%) was lower than in female (91.26%), but there was no significant difference (x2=0.222, P >0.05). Conclusions The positive rate of NAbs was the highest from 10 to 70 days after the second dose of vaccine, and the positive rate gradually decreased as time went by. There was a high linear correlation between COVID-19 NAbs and IgM/IgG antibodies in vaccinators, suggesting that in cases where NAbs cannot be detected, IgM/IgG antibodies can be detected instead. The level of NAbs produced after vaccination was affected by age, but not by gender. The highest levels of NAbs were produced between shots 21 to 56 days apart, suggesting that 21 to 56 days between shots is suitable for vaccination.

scholarly journals SARS-CoV-2 Neutralizing Antibody Levels Post COVID-19 Vaccination Based on ELISA Method—A Small Real-World Sample Exploration

Vaccines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1139
Author(s):  
Xiaoguang Li ◽  
Chao Liang ◽  
Xiumei Xiao
Keyword(s):  
Neutralizing Antibodies ◽  
Detection Rate ◽  
Neutralizing Antibody ◽  
Population Characteristics ◽  
Detection Rates ◽  
Positive Detection Rate ◽  
Significant Difference ◽  
Positive Rate ◽  
Antibody Levels

This study investigated the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) neutralizing antibodies following inoculation with the coronavirus disease (COVID-19) vaccine. From June to July 2021, 127 participants who had completed COVID-19 vaccination (inactivated SARS-CoV-2 vaccine, 64; CoronaVac, 61; CanSino, 2) were recruited and tested using SARS-CoV-2 neutralizing antibody kits. The positive detection rate (inhibition of neutralizing antibodies ≥ 30%) was calculated and stratified according to population characteristics and inoculation time. The positive rate of neutralizing antibody was 47.22% (17/36) in men and 53.85% (49/91) in women, and 54.55% (24/44) in BMI ≥ 24 and 50.60% (42/83) in BMI < 24. Age was stratified as 20–29, 30–39, 40–49, and ≥50; positive detection rates of SARS-CoV-2 neutralizing antibodies were observed in 60.00% (24/40), 50.00% (21/42), 48.39% (15/31), and 42.86% (6/14), respectively, but with no significant difference (x2 = 1.724, p = 0.632). Among 127 vaccinated participants, 66 (51.97%) were positive. The positive detection rate was 63.93% (39/61) with CoronaVac and 42.19% (27/64) with the inactivated SARS-CoV-2 vaccine (significance x2 = 5.927, p = 0.015). Multivariate analysis revealed a significant difference in vaccination times, with average vaccination weeks in the positive and negative groups of 11.57 ± 6.48 and 17.87 ± 9.17, respectively (t= −4.501, p < 0.001). The positive neutralizing antibody rate was 100.00%, 60.00%, 58.33%, 55.56%, 43.14%, 28.57%, and 0.00% at 2–4, 5–8, 9–12, 13–16,17–20, 21–24, and >24 weeks, respectively (x2 = 18.030, p = 0.006). Neutralizing antibodies were detected after COVID-19 inoculation, with differences relating to inoculation timing. This study provides a reference for vaccine evaluation and follow-up immunization strengthening.

scholarly journals Rapid evaluation of neutralizing antibodies in COVID-19 patients

2020 ◽  
Author(s):  
Pingping Zhang ◽  
Baisheng Li ◽  
Wei Min ◽  
Xiaohui Wang ◽  
Zhencui Li ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
High Efficiency ◽  
Point Of Care ◽  
Herd Immunity ◽  
Neutralizing Antibody ◽  
Rapid Evaluation ◽  
Serum Samples ◽  
Protection Rate ◽  
Positive Rate ◽  
Polymerase Chain

The ongoing coronavirus disease 2019 (COVID-19) pandemic calls for a method to rapidly and conveniently evaluate neutralizing antibody (NAb) activity in patients. Here, an up-conversion phosphor technology-based point-of-care testing (UPT-POCT) and a microneutralization assay were employed to detect total antibodies against the receptor-binding domain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein and NAb activity in COVID-19 patients' sera, respectively, in order to determine if UPT-POCT could be used as a surrogate method for rapid evaluation of serum NAb activity in COVID-19 patients. In total, 519 serum samples from 213 recovered and 99 polymerase chain reaction re-positive (RP) COVID-19 patients were used in this report. We found that UPT-POCT reporting values correlated highly with NAb titers from 1:4 to 1:1024, with a correlation coefficient r = 0.9654 (P < 0.001), as well as protection rate against RP (r = 0.9886, P < 0.0001). As a significant point for reducing re-positive rate, UPT-POCT values of 4.380, corresponding to NAb titer of 1:64, may be appropriate as an indicator for evaluating high efficiency of protection. This study demonstrates that the quantitative lateral flow based UPT-POCT, could be used to rapidly evaluate NAb titer, which is of importance for assessing vaccine immunization efficacy, herd immunity, and screening patient plasma for high NAbs.

scholarly journals A longitudinal study of SARS-CoV-2-infected patients reveals a high correlation between neutralizing antibodies and COVID-19 severity

2021 ◽  
Author(s):  
Vincent Legros ◽  
Solène Denolly ◽  
Manon Vogrig ◽  
Bertrand Boson ◽  
Eglantine Siret ◽  
...  
Keyword(s):  
Intensive Care ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Surface Protein ◽  
Humoral Response ◽  
Neutralizing Antibody ◽  
Rapid Decline ◽  
Serum Samples ◽  
Immune Correlates ◽  
Human Coronaviruses

AbstractUnderstanding the immune responses elicited by SARS-CoV-2 infection is critical in terms of protection against reinfection and, thus, for public health policy and vaccine development for COVID-19. In this study, using either live SARS-CoV-2 particles or retroviruses pseudotyped with the SARS-CoV-2 S viral surface protein (Spike), we studied the neutralizing antibody (nAb) response in serum samples from a cohort of 140 SARS-CoV-2 qPCR-confirmed infections, including patients with mild symptoms and also more severe forms, including those that required intensive care. We show that nAb titers correlated strongly with disease severity and with anti-spike IgG levels. Indeed, patients from intensive care units exhibited high nAb titers; conversely, patients with milder disease symptoms had heterogeneous nAb titers, and asymptomatic or exclusive outpatient-care patients had no or low nAbs. We found that nAb activity in SARS-CoV-2-infected patients displayed a relatively rapid decline after recovery compared to individuals infected with other coronaviruses. Moreover, we found an absence of cross-neutralization between endemic coronaviruses and SARS-CoV-2, indicating that previous infection by human coronaviruses may not generate protective nAbs against SARS-CoV-2. Finally, we found that the D614G mutation in the spike protein, which has recently been identified as the current major variant in Europe, does not allow neutralization escape. Altogether, our results contribute to our understanding of the immune correlates of SARS-CoV-2-induced disease, and rapid evaluation of the role of the humoral response in the pathogenesis of SARS-CoV-2 is warranted.

scholarly journals Antibody titers measured by commercial assays are correlated with neutralizing antibody titers calibrated by international standards

2021 ◽  
Author(s):  
Yu-An Kung ◽  
Chung-Guei Huang ◽  
Sheng-Yu Huang ◽  
Kuan-Ting Liu ◽  
Peng-Nien Huang ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Geometric Mean ◽  
Neutralizing Antibody ◽  
Diagnostic Techniques ◽  
International Standards ◽  
World Health ◽  
Serum Samples ◽  
Antibody Titers ◽  
Health Organization

The World Health Organization (WHO) has highlighted the importance of an international standard (IS) for SARS-CoV-2 neutralizing antibody titer detection, with the aim of calibrating different diagnostic techniques. In this study, IS was applied to calibrate neutralizing antibody titers (IU/mL) and binding antibody titers (BAU/mL) in response to SARS-CoV-2 vaccines. Serum samples were collected from participants receiving the Moderna (n = 20) and Pfizer (n = 20) vaccines at three time points: pre-vaccination, after one dose, and after two doses. We obtained geometric mean titers of 1404.16 and 928.75 IU/mL for neutralizing antibodies after two doses of the Moderna and Pfizer vaccines, respectively. These values provide an important baseline for vaccine development and the implementation of non-inferiority trials. We also compared three commercially available kits from Roche, Abbott, and MeDiPro for the detection of COVID-19 antibodies based on binding affinity to S1 and/or RBD. Our results demonstrated that antibody titers measured by commercial assays are highly correlated with neutralizing antibody titers calibrated by IS.

Prevalence and Persistence of Maternal Dengue Neutralizing Antibodies in Infants From Central and Southern Thailand: A Retrospective Cohort Study

2019 ◽  
Vol 31 (4) ◽  
pp. 288-295 ◽  
Author(s):  
Adrienne Guignard ◽  
François Haguinet ◽  
Stéphanie Wéry ◽  
Phirangkul Kerdpanich
Keyword(s):  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Geometric Mean ◽  
Neutralizing Antibody ◽  
Maternal Antibodies ◽  
Childhood Immunization ◽  
Serum Samples ◽  
Denv Serotypes ◽  
Antibody Titers ◽  
Antibody Kinetics

Understanding maternal dengue virus (DENV) neutralizing antibody kinetics in infants remains timely to develop a safe and effective childhood immunization. This retrospective study evaluated the prevalence and persistence of maternal antibody titers against DENV serotypes 1 to 4 in 139 Thai infants at 2, 6, and 7 months of age, using serum samples collected in a vaccination trial ( http://clinicaltrials.gov ; NCT00197275). Neutralizing antibodies against all 4 DENV serotypes were detected in 87.8% and 22.9% of infants at 2 and 7 months, respectively. At 2 months, DENV-4 neutralizing antibody geometric mean titers were notably lower (80) compared with DENV-1 to DENV-3 (277-471). Our results corroborate previous findings that DENV-1 to DENV-4 maternal antibodies persist at 7 months despite titers decrease from 2 months onwards. As persisting maternal antibodies may inhibit immune responses in DENV-vaccinated infants, a comprehensive understanding of DENV antibody kinetics is required in the perspective of vaccine development for infants.

scholarly journals Taking a Breath of the Wild: Are geoscientists more effective than non-geoscientists in determining whether game-world landscapes are realistic?

2019 ◽  
Author(s):  
Rolf Hut ◽  
Casper Albers ◽  
Sam Illingworth ◽  
Chris Skinner
Keyword(s):  
Real World ◽  
Great Opportunity ◽  
Van Gogh ◽  
Landscape Features ◽  
The Real ◽  
Game World ◽  
Significant Difference ◽  
Missed Opportunity

Abstract. From the wilderness of Hyrule, the entire continent of Tamriel, to Middle Earth, players of videogames are exposed to wonderous, fantastic, but ultimately fake, landscapes. Given the time people may spend in these worlds, compared to the time they spend being trained in geoscience, we wondered if expert geoscientists would differ from non-geoscientists in whether they judge the landscapes in these games to be realistic. Since games have a great opportunity for tangential learning it would be a missed opportunity if it turns out that features obviously fake to geoscientists are perceived as plausible by non-geoscientists. To satisfy our curiosity and answer this question we conducted a survey where we asked people to judge both photos from real landscapes as well as screenshots from the recent The Legend of Zelda: Breath of the Wild videogame on how likely they thought the features in the picture were to exist in the real world. Since game-world screenshots are easily identified based on their rendered, pixaleted nature, we pre-processed all pictures with an artistic Van Gogh filter that removed the rendered nature, but retained the dominant landscape features. We found that there is a small but significant difference between geoscientists and non-geoscientists with geoscientists being slightly better at judging which pictures are from the real world versus from the game world. While significant the effect is small enough to conclude that fantastical worlds in games can be used for tangential learning on geoscientific subjects.

The Clinical Application Value of Multiple Combination Food Intolerance Testing

2020 ◽  
Author(s):  
Shudong LIN ◽  
Xiujing YANG ◽  
Ying XING ◽  
Xingye WANG ◽  
Yadong LI
Keyword(s):  
Gastrointestinal Symptoms ◽  
Egg White ◽  
The Body ◽  
Food Intolerance ◽  
Igg Antibodies ◽  
Significant Difference ◽  
Positive Rate ◽  
Specific Igg ◽  
Symptom Group ◽  
Specific Igg Antibodies

Background: We aimed to investigate the clinical value of detecting 14 food intolerances. Methods: A total of 312 patients with food intolerance enrolled in the Third Affiliated Hospital of Qiqihar Medical University (Qiqihar, China) from Feb 2016 to Feb 2017 were selected. ELISA was used to detect intolerance specific IgG antibodies for 14 foods (pork, chicken, beef, shrimp, fish, crab, egg white/yolk, tomato, mushroom, milk, corn, rice, soybean, wheat). Results: The highest average positive rate of the patients was 42.31% for the crab, followed by shrimp 21.15%, egg white/yolk 18.27% and milk 16.99%. The positive rate from high to low was crab, shrimp, egg white/yolk, milk, fish, corn, soybeans, tomatoes, rice, mushrooms, wheat, pork, beef, chicken. There were significant differences in the specific IgG antibody positive rates between shrimp, soybean and wheat in the skin symptoms group, gastrointestinal symptoms group, respiratory symptom group and nervous system symptom group (P<0.05). There was a significant difference in the positive rate of specific IgG antibodies between shrimp, crab and egg white/yolk in the adolescent group, the middle-aged group and the elderly group (P<0.05). Conclusion: The detection of food-specific IgG antibodies can help to determine which food intolerance caused the disease, and then adopt a fasting or diet method to avoid eating unsuitable foods and continually damaging the body, thus maintaining good health. The detection method provides a new idea for the diagnosis and prevention of diseases.

Prescribing patterns for FOLFIRINOX in the real world.

2018 ◽  
Vol 36 (4_suppl) ◽  
pp. 463-463
Author(s):  
Chad Michael Guenther ◽  
Nizar Bhulani ◽  
Adam Korenke ◽  
Jenny Jing Li ◽  
Leticia Khosama ◽  
...  
Keyword(s):  
Real World ◽  
Prescribing Patterns ◽  
Comprehensive Cancer Center ◽  
Cancer Center ◽  
Bivariate Analysis ◽  
Treatment Delays ◽  
The Real ◽  
Significant Difference ◽  
Ed Visits ◽  
Dose Modifications

463 Background: FOLFIRINOX therapy is associated with improved outcome in patients with gastrointestinal cancers. The regimen can be associated with significant toxicity and empiric dose modifications are often used. We analyzed 1) real-world prescribing patterns of FOLFIRINOX and 2) toxicity of therapy. Methods: Patients undergoing FOLFIRINOX chemotherapy at an academic, NCI-Designated Comprehensive Cancer Center were identified and electronic medical records reviewed. Patients who received at least one dose of FOLFIRINOX were included. Chemotherapy dose, growth factor use and toxicity data was abstracted for the first 8 weeks. ‘Standard FOLFIRNOX’ was defined as the regimen utilized by Conroy et al (NEJM 2011). Any empiric reduction/withholding of drug dose for cycle 1 was classified as ‘modified FOLFIRINOX’. Bivariate analysis was performed on the data. Results: There were 111 patients seen between 5/2011-3/2017 and 94% had pancreatic cancer. Age range was 29-87 years and 52% were female. 59% received ‘modified FOLFIRINOX’ and 20% received empiric growth factors. Line of therapy for standard vs modified respectively was 71.1% vs 45.5% for 1st, 17.8% vs 36.4% for 2nd, and 11.1% vs 18.2% for beyond 2nd (p = 0.03). Patients with ‘modified FOLFIRINOX’ were more likely to have metastatic disease (p = 0.01), have received second line or beyond, and higher ECOG score (p = 0.03). Patients with ‘modified FOLFIRINOX’ had a trend toward fewer treatment-related ED visits or hospitalization vs ‘standard FOLFIRINOX’ (27.2% vs 42.2% p = 0.10) and fewer treatment delays (25.8% vs 42.2% p = 0.07). Conclusions: In the real world setting, a majority of patients on FOLFIRINOX receive empiric dose modifications. Although modified dose did not translate to a significant difference in ED visits, hospitalizations or treatment delays, there was a trend toward fewer events.

scholarly journals Prevalence of Neutralizing Antibodies against Different Rotavirus Serotypes in Children with Severe Rotavirus-Induced Diarrhea and Their Mothers

2004 ◽  
Vol 11 (1) ◽  
pp. 186-194 ◽  
Author(s):  
Pratibha G. Ray ◽  
Shobhana D. Kelkar
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Serum Samples ◽  
Serotype A ◽  
Convalescent Phase ◽  
Human Rotavirus ◽  
Child Patients ◽  
Child Patient ◽  
Paired Serum ◽  
Rotavirus Diarrhea

ABSTRACT Neutralizing antibody (NAb) responses to different rotavirus serotypes were compared in 64 convalescent-phase serum samples from hospitalized rotavirus-positive children less than 2 years of age and their mothers. Compared to the child patients, the mothers showed significantly higher NAb positivity to animal rotavirus serotypes G3 simian (96.88%), G6 bovine (85.94%), and G10 bovine (25.0%) and to human rotavirus serotypes G8 (79.69%) and G3 (57.81%) (P < 0.01 for each) but not to human serotypes G1, G2, G4, and G9 (P > 0.05). The overall prevalence of NAb among the child patients was low for human rotavirus serotypes G1 (20.31%) and G3 (21.8%). The comparative NAb response in individual mother-child paired serum samples was analyzed against each rotavirus serotype. A substantial number of child patients showed higher NAb titers than their mothers to serotypes G1, G2, G4, and G9, indicating that these serotypes are the major serotypes causing rotavirus diarrhea among the children of Pune, India. In these cases, the mothers were either negative or had lower titers of NAbs than their children. Correlation was observed between the infecting serotype and child patient serum that showed a homologous NAb response at a higher level than that of the mother. It appears that when the level of NAb to a particular serotype is higher among child patients than among their mothers, that serotype is the infecting serotype, and that low titers of NAb among the mothers predispose the children to infection with that serotype, if the serotype is in circulation.

scholarly journals Neutralization of SARS-CoV-2 Omicron variant by sera from BNT162b2 or Coronavac vaccine recipients

2021 ◽  
Author(s):  
Lu Lu ◽  
Bobo Mok ◽  
Linlei Chen ◽  
Jacky Chan ◽  
Owen Tsang ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Neutralizing Antibody ◽  
World Health ◽  
Whole Genome Sequence ◽  
Live Virus ◽  
Significant Difference ◽  
Antibody Titers ◽  
Ancestral Virus ◽  
Health Organization

Background The SARS-CoV-2 Omicron variant, designated as a Variant of Concern(VOC) by the World Health Organization, carries numerous spike protein mutations which have been found to evade neutralizing antibodies elicited by COVID-19 vaccines. The susceptibility of Omicron variant by vaccine-induced neutralizing antibodies are urgently needed for risk assessment. Methods Omicron variant strains HKU691 and HKU344-R346K were isolated from patients using TMPRSS2-overexpressing VeroE6 cells. Whole genome sequence was determined using nanopore sequencing. Neutralization susceptibility of ancestral lineage A virus and the Omicron, Delta and Beta variants to sera from 25 BNT162b2 and 25 Coronavac vaccine recipients was determined using a live virus microneutralization assay. Results The Omicron variant strain HKU344-R346K has an additional spike R346K mutation, which is present in 8.5% of strains in GISAID database. Only 20% and 24% of BNT162b2 recipients had detectable neutralizing antibody against the Omicron variant HKU691 and HKU344-R346K, respectively, while none of the Coronavac recipients had detectable neutralizing antibody titer against either Omicron isolates. For BNT162b2 recipients, the geometric mean neutralization antibody titers(GMT) of the Omicron variant isolates(5.43 and 6.42) were 35.7-39.9-fold lower than that of the ancestral virus(229.4), and the GMT of both omicron isolates were significantly lower than those of the beta and delta variants. There was no significant difference in the GMT between HKU691 and HKU344-R346K. Conclusions Omicron variant escapes neutralizing antibodies elicited by BNT162b2 or CoronaVac. The additional R346K mutation did not affect the neutralization susceptibility. Our data suggest that the Omicron variant may be associated with lower COVID-19 vaccine effectiveness.

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